scholarly journals Climatology and trend of cold waves over India during 1971-2010

MAUSAM ◽  
2021 ◽  
Vol 67 (3) ◽  
pp. 651-658
Author(s):  
SMITHA ANIL NAIR ◽  
D. S. PAI ◽  
M. RAJEEVAN
Keyword(s):  
El Niño ◽  
El Nino ◽  
Central India ◽  
La Niña ◽  
Cold Weather ◽  
Cold Wave ◽  
Cold Waves ◽  
La Nina ◽  
Spatial Coverage ◽  
Enso Phases

Using Cold Wave (CW) information of 86 stations from Indian main land during the cold weather season (November to March) for the last 40 years (1971-2010), various statistical aspects of cold waves (CWs) and severe cold waves (SCWs) such as climatology and trend were examined. The link of CWs/SCWs with ENSO phases (La Nina & El Nino) was also examined. It was observed that many stations from north, northwest, east and central India together named as core CW zone (CCZ) experienced highest number of CW/SCW waves with relatively higher frequency during January.  Noticeable decrease (increase) in the frequency and spatial coverage of CW/SCW days compared to their climatological values were observed during the El Nino (La Nina) years. There were significant decreasing trends in the CW/SCW days over most of the stations from CCZ. The total number of CW/SCW days/per decade over CCZ showed noticeable decrease during the recent decades 1991-2000 and 2001-2010, which coincided with the warmest decades for the country as well as for the globe. Associated with intense and persistent CW/SCW events, large human mortality were reported during some years of the study period.

Errors in the winter temperature response to ENSO over North America in seasonal forecast models

2021 ◽  
pp. 1-35
Author(s):  
Seon Tae Kim ◽  
Yun-Young Lee ◽  
Ji-Hyun Oh ◽  
A-Young Lim
Keyword(s):  
North America ◽  
El Niño ◽  
El Nino ◽  
Seasonal Forecast ◽  
La Niña ◽  
Forecast Performance ◽  
Atmospheric Teleconnection ◽  
La Nina ◽  
Forecast Models ◽  
Enso Phases

AbstractThis study presents the ability of seasonal forecast models to represent the observed mid-latitude teleconnection associated with El Niño-Southern Oscillation (ENSO) events over the North American region for the winter months of December, January, and February. Further, the impacts of the associated errors on regional forecast performance for winter temperatures are evaluated, with a focus on one-month lead time forecasts. In most models, there exists a strong linear relationship of temperature anomalies with ENSO and, thus, a clear anomaly sign separation between both ENSO phases persists throughout the winter, whereas linear relationships are weak in observations. This leads to a difference in the temperature forecast performance between the two ENSO phases. Forecast verification scores show that the winter season warming (cooling) events during El Niño in northern (southern) North America are more correctly forecasted in the models than the cooling (warming) events during La Niña. One possible reason for this result is that the remote atmospheric teleconnection pattern in the models is almost linear or symmetric between the El Niño and La Niña phases. The strong linear atmospheric teleconnection appears to be associated with the models’ failure in simulating the westward shift of the tropical Pacific rainfall response for the La Niña phase compared to that for the El Niño phase, which is attributed to the warmer central tropical Pacific in the models. This study highlights that understanding how the predictive performance of climate models varies according to El Niño or La Niña phases is very important when utilizing predictive information from seasonal forecast models.

scholarly journals Long-Term Variation in Survival of A Neotropical Freshwater Turtle: Habitat and Climatic Influences

Diversity ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 97 ◽  
Author(s):  
Mario F. Garcés-Restrepo ◽  
John L. Carr ◽  
Alan Giraldo
Keyword(s):  
El Niño ◽  
Transition Probabilities ◽  
El Nino ◽  
Southern Oscillation ◽  
La Niña ◽  
Freshwater Turtle ◽  
Freshwater Turtles ◽  
La Nina ◽  
Enso Phases

Few long-term demographic studies have been conducted on freshwater turtles of South America, despite the need for this type of inquiry to investigate natural variation and strengthen conservation efforts for these species. In this study, we examined the variation in demography of the Chocoan River Turtle (Rhinoclemmys nasuta) based on a population from an island locality in the Colombian Pacific region between 2005 and 2017. We calculated survival, recapture, and transition probabilities, and the effects of stream substrate and El Niño–Southern Oscillation (ENSO) phases (El Niño, Neutral, La Niña) on these variables using a multi-state model. We found differences in survival probabilities between ENSO phases, likely as a consequence of an increase in flood events. In addition, we found support for survival being greater in muddy streams than rocky streams, possibly because it is easier to escape or hide in mud substrates. Recapture probabilities varied by life stages; differences in the probability of recapture between size classes were associated with the high fidelity to territories by adults. The present increases in frequency and severity of El Niño and La Niña may exacerbate the consequences of climatic regimes on natural populations of turtles by increasing the mortality caused by drastic phenomena such as floods.

scholarly journals Effect of El Niño–Southern Oscillation on the Number of Leaching Rain Events in Florida and Implications on Nutrient Management for Tomato

2010 ◽  
Vol 20 (1) ◽  
pp. 120-132 ◽  
Author(s):  
Clyde W. Fraisse ◽  
Zhengjun Hu ◽  
Eric H. Simonne
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Growing Season ◽  
La Niña ◽  
El Nino Southern Oscillation ◽  
Rainfall Events ◽  
La Nina ◽  
Seepage Irrigation ◽  
Enso Phases

Most of the winter vegetable production in the southeastern United States is located in Florida. High-value vegetable crops are grown under intensive fertilization and irrigation management practices using drip, overhead, or seepage irrigation systems. Rainfall events may raise the water table in fields irrigated by seepage irrigation resulting in leaching of nutrients when the level is lowered to remove excess water. The objective of this study was to assess the effect of El Niño–Southern Oscillation (ENSO) phases on rainfall distribution and leaching rain occurrences during the fall, winter, and spring tomato (Solanum lycopersicum) growing seasons using long-term weather records available for main producing areas. Differences in fall growing season mean precipitation during El Niño, La Niña, and neutral years were found to be nonsignificant. Winter and spring mean precipitations during El Niño, La Niña, and neutral years were found to be significantly different. Winter and spring average rainfall amounts during La Niña and neutral years were lower than during El Niño years. During El Niño years, at least one leaching rainfall event of 1.0 inch or more in 1 day occurred at all locations and all planting seasons and two of these events occurred in more than 9 of 10 years except during the winter and spring planting seasons at the Tamiami Trail station located in Miami–Dade County. During the fall growing season of El Niño years, three to four 1.0 inch or more in 1-day leaching rainfalls may be expected at least 4 of 5 years at all locations. In the case of larger leaching rainfall events (3.0 inches or more recorded in 3 days or 4.0 inches or more recorded in 7 days), the probability of having at least one event was mostly less than 0.80. Based on these results, nitrogen fertilizer supplemental applications of 30 to 120 lb/acre could be applied during the fall growing season of all ENSO phases and during all planting seasons of El Niño years. Using current fertilizer prices, one supplemental fertilizer application of 30 lb/acre nitrogen and 16.6 lb/acre potassium costs $55/acre. Assuming a median wholesale price of $12 per 25-lb box, this additional cost may be offset by a modest yield increase of 4.6 boxes/acre (compared with a typical 2500 25-lb box/acre marketable yield). These results suggest that ENSO phases could be used to predict supplemental fertilizer needs for tomato, but adjustments to local weather conditions may be needed.

scholarly journals Impacts of fire emissions and transport pathways on the interannual variation of CO in the tropical upper troposphere

2014 ◽  
Vol 14 (8) ◽  
pp. 4087-4099 ◽  
Author(s):  
L. Huang ◽  
R. Fu ◽  
J. H. Jiang
Keyword(s):  
El Niño ◽  
Interannual Variation ◽  
El Nino ◽  
La Niña ◽  
Transport Pathway ◽  
Transport Pathways ◽  
Upper Troposphere ◽  
La Nina ◽  
Enso Phases ◽  
Tropical Upper Troposphere

Abstract. This study investigates the impacts of fire emission, convection, various climate conditions and transport pathways on the interannual variation of carbon monoxide (CO) in the tropical upper troposphere (UT), by evaluating the field correlation between these fields using multi-satellite observations and principle component analysis, and the transport pathway auto-identification method developed in our previous study. The rotated empirical orthogonal function (REOF) and singular value decomposition (SVD) methods are used to identify the dominant modes of CO interannual variation in the tropical UT and to study the coupled relationship between UT CO and its governing factors. Both REOF and SVD results confirm that Indonesia is the most significant land region that affects the interannual variation of CO in the tropical UT, and El Niño–Southern Oscillation (ENSO) is the dominant climate condition that affects the relationships between surface CO emission, convection and UT CO. In addition, our results also show that the impact of El Niño on the anomalous CO pattern in the tropical UT varies strongly, primarily due to different anomalous emission and convection patterns associated with different El Niño events. In contrast, the anomalous CO pattern in the tropical UT during La Niña period appears to be less variable among different events. Transport pathway analysis suggests that the average CO transported by the "local convection" pathway (ΔCOlocal) accounts for the differences of UT CO between different ENSO phases over the tropical continents during biomass burning season. ΔCOlocal is generally higher over Indonesia–Australia and lower over South America during El Niño years than during La Niña years. The other pathway ("advection within the lower troposphere followed by convective vertical transport") occurs more frequently over the west-central Pacific during El Niño years than during La Niña years, which may account for the UT CO differences over this region between different ENSO phases.

ANALISIS DAERAH RAWAN KEKERINGAN LAHAN JAGUNG BERDASARKAN IKLIM OLDEMAN DAN KETERSEDIAN AIR TANAH DI NUSA TENGGARA TIMUR SAAT PERIODE EL NINO DAN LA NINA

2019 ◽  
Vol 3 ◽  
pp. 1219
Author(s):  
Oki Adrianto ◽  
Sudirman Sudirman ◽  
Suwandi Suwandi
Keyword(s):  
El Niño ◽  
El Nino ◽  
La Niña ◽  
La Nina

Perekonomian Provinsi Nusa Tenggara Timur secara sektoral masih didominasi sektor pertanian.Tanaman jagung menjadi salah satu produksi tanaman pangan terbesar berdasarkan data dari Dinas Pertanian dan Perkebunan Provinsi Nusa Tenggara Timur tahun 2015. Peningkatan produksi pertanian dapat dilakukan melalui berbagai strategi adaptasi dan upaya penanganan bencana, salah satu upaya tersebut adalah dengan penyediaan informasi iklim terkait penentuan daerah-daerah rawan kekeringan. Tujuan dari penelitian ini adalah untuk mengetahui sebaran wilayah rawan kekeringan lahan jagung bulanan di Provinsi Nusa Tenggara Timur saat kondisi El Nino dan La Nina dengan periodeisasi bulanan januari hingga desember. Data yang digunakan dalam penelitian ini adalah data curah hujan rata rata bulanan di 19 pos hujan di Provinsi Nusa Tenggara Timur dan suhu udara rata-rata bulanan dihitung menggunakan pendekatan teori Brack dengan titik referensi Stasiun Klimatologi Lasiana Kupang. Periode dari masing-masing data yang digunakan adalah dari tahun 1991 dan 1997 digunakan sebagai tahun El Nino dan tahun 1999 dan 2010 digunakan sebagai tahun La Nina. Metode yang digunakan untuk menentukan tingkat rawan kekeringan dengan menggunakan pembobotan berdasarkan penjumlahan bobot tipe iklim Oldeman dan bobot ketersediaan air tanah. Hasil penelitian menunjukkan sebaran daerah kekeringan di Provinsi Nusa Tenggara Timurpada tahun el nino lebih luas dibandingkan tahun la nina.

A Influência dos fenômenos El Niño e La Niña sobre a dinâmica climática da região Amazônica

2018 ◽  
Vol 1 ◽  
pp. e2018014
Author(s):  
Samya de Freitas MOREIRA ◽  
Cleiciane Silva da CONCEIÇÃO ◽  
Milla Cristina Santos da CRUZ ◽  
Antônio PEREIRA JÚNIOR
Keyword(s):  
El Niño ◽  
El Nino ◽  
La Niña ◽  
La Nina

Caracterização climática da temperatura do ar em Veranópolis, Rio Grande do Sul

Agrometeoros ◽  
2020 ◽  
Vol 26 (2) ◽  
Author(s):  
Amanda Heemann Junges
Keyword(s):  
El Niño ◽  
El Nino ◽  
Rio Grande ◽  
La Niña ◽  
Rio Grande Do Sul ◽  
La Nina

Estudos locais de caraterização e variabilidade climática são fundamentais para geração de informações mais adaptadas às atividades agrícolas desenvolvidas em um município ou região. O objetivo desse trabalho foi caracterizar climaticamente e analisar a influência de eventos El Niño Oscilação Sul (ENOS) na série 1956-2015 de temperatura do ar de Veranópolis, RS. Para caracterização climática foram estabelecidas estatísticas descritivas das temperaturas do ar máximas, mínimas e médias mensais, estacional e anual na série e normal climatológica padrão 1961- 1990. Para identificação de diferenças entre estações e influência de eventos ENOS, os dados foram submetidos à análise de variância e teste de Duncan. Os resultados indicaram que a temperatura média anual é de 17,3ºC, variando entre 12,7ºC (julho) e 21,8ºC (janeiro). O clima é do tipo Cfb, de acordo com a classificação climática de Köppen e TE (temperado) na classificação climática do Estado. Temperaturas mínimas médias mensais inferiores a 10ºC ocorrem de maio a setembro, período de maior variabilidade interanual das temperaturas máximas (desvio padrão entre 1,5º e 1,8ºC), mínimas (1,6-1,8ºC) e médias mensais (1,4-1,7ºC). Anos de La Niña possuem temperaturas médias estacionais inferiores as de El Niño, embora diferenciação em relação a neutros ocorra somente para temperaturas mínimas na primavera e máximas no outono.

Rendimento de grãos de soja e de milho, no Rio Grande do Sul, não difere entre eventos El Niño Oscilação Sul

Agrometeoros ◽  
2018 ◽  
Vol 26 (1) ◽  
Author(s):  
Ronaldo Matzenauer ◽  
Bernadete Radin ◽  
Alberto Cargnelutti Filho
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Rio Grande ◽  
La Niña ◽  
Rio Grande Do Sul ◽  
La Nina ◽  
Significant Difference ◽  
Income Data ◽  
The Relationship

O objetivo deste trabalho foi avaliar a relação entre o fenômeno El Niño Oscilação Sul - ENOS e o rendimento de grãos de soja e de milho no Rio Grande do Sul e verificar a hipótese de que os eventos El Niño são favoráveis e os eventos La Niña são prejudiciais ao rendimento de grãos das culturas. Foram utilizados dados de rendimento de grãos dos anos agrícolas de 1974/75 a 2016/17, e relacionados com as ocorrências de eventos ENOS. Foram analisados os dados de rendimento observados na colheita e os dados estimados com a remoção da tendência tecnológica. Os resultados mostraram que não houve diferença significativa do rendimento médio de grãos de soja e de milho na comparação entre os eventos ENOS. Palavras-chave: El Niño, La Niña, safras agrícolas. Abstract – The objective of this work was to evaluate the relationship between the El Niño Southern Oscillation (ENSO) phenomenon with the grain yield of soybean and maize in Rio Grande do Sul state, Brazil and to verify the hypothesis that the El Niño events are favorable and the La Niña events are harmful to the culture’s grain yields. Were used data from the agricultural years of 1974/75 to 2016/17, and related to the occurrence of ENOS events. We analyzed income data observed at harvest and estimated data with technological tendency was removed. The results showed that there was no significant difference in the average yield of soybeans and corn in the comparison between events.

Atmospheric teleconnection patterns associated with severe and mild ice cover on the Great Lakes, 1963–2011

2012 ◽  
Vol 47 (3-4) ◽  
pp. 421-435 ◽  
Author(s):  
Xuezhi Bai ◽  
Jia Wang
Keyword(s):  
North America ◽  
Great Lakes ◽  
El Niño ◽  
El Nino ◽  
Ice Cover ◽  
Reanalysis Data ◽  
Teleconnection Pattern ◽  
La Niña ◽  
Atmospheric Teleconnection ◽  
La Nina

Atmospheric teleconnection circulation patterns associated with severe and mild ice cover over the Great Lakes are investigated using the composite analysis of lake ice data and National Center of Environmental Prediction (NCEP) reanalysis data for the period 1963–2011. The teleconnection pattern associated with the severe ice cover is the combination of a negative North Atlantic Oscillation (NAO) or Arctic Oscillation (AO) and negative phase of Pacific/North America (PNA) pattern, while the pattern associated with the mild ice cover is the combination of a positive PNA (or an El Niño) and a positive phase of the NAO/AO. These two extreme ice conditions are associated with the North American ridge–trough variations. The intensified ridge–trough system produces a strong northwest-to-southeast tilted ridge and trough and increases the anomalous northwesterly wind, advecting cold, dry Arctic air to the Great Lakes. The weakened ridge–trough system produces a flattened ridge and trough, and promotes a climatological westerly wind, advecting warm, dry air from western North America to the Great Lakes. Although ice cover for all the individual lakes responds roughly linearly and symmetrically to both phases of the NAO/AO, and roughly nonlinearly and asymmetrically to El Niño and La Niña events, the overall ice cover response to individual NAO/AO or Niño3.4 index is not statistically significant. The combined NAO/AO and Niño3.4 indices can be used to reliably project severe ice cover during the simultaneous –NAO/AO and La Niña events, and mild ice cover during the simultaneous +NAO/AO and El Niño events.

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